Performance drop to 10 FPS system-wide after playing for a while on 26.2

The Issue:

After playing the game for some time, independent of the in-game activity, the performance would suddenly drop heavily. Before the main issue triggered, looking at scoreboards would cause massive frame drops from high FPS down to 20 FPS. Eventually, a permanent drop to 10 FPS would happen.

​Once the 10 FPS drop occurred, it affected the entire operating system (creating a system-wide slideshow effect), even after closing Minecraft. Computer temperatures and resource usage (CPU/RAM/GPU) remained completely normal during the lag. The only temporary fix was restarting the PC, which immediately restored performance